Synthesis Of New N,N-Disubstituted Aryl- And Alkylaryl Sulphonamides And Their Antimicrobial Properties

ABSTRACT

The reaction of α–toluenesulphonyl chloride with various readily available amino acids in basic medium afforded α–toluenesulphonamides (1a-k) which had their acid function subsequently amidated with diethyl amine to obtain their corresponding new N,Ndiethylalkanamido substituted α–toluenesulphonamide derivatives (2a-k). The electrophilic addition of p-toluenesulphonyl chloride with various amino acids' nitrogen gave p-tolylsulphonamide derivatives (4a-k) which upon further reaction of the corresponding acid chloride with diethylamine afforded N, N-diethylamido substituted moieties (5a-k). Sulphonylation of the amino acids with benzenesulphonyl chloride yielded benzenesulphonamides derivatives, (7a-k) which were used as the intermediate for the synthesis of the N′, N′-diethylated alkanamido benzenesulphonamide derivatives, (8a-k). The chemical structures of synthesized compounds were confirmed using elemental analysis and spectroscopic tools which include Fourier Transform-Infrared (FT-IR), Mass Spectra, proton and carbon-13 Nuclear Magnetic Resonance (1 H- and 13CNMR). The antimicrobial properties of the synthesized sulphonamides (fifty five compounds) were determined on Staphylococcus aureus and Escherichia coli using agar diffusion method where 1-(benzylsulphonyl)pyrrolidine-2-carboxylic acid, (1a) was the most active compound against Staphylococcus aureus at MIC value of 1.8 µg/mL while 4-(3-(diethylamino)-3-oxo-2-(phenylmethylsulphonamido)propyl)phenyl phenyl methane sulphonate (2k) and N,N-diethyl-2-(4-methylphenylsulphonamido)-3-phenyl propanamide (5j) were the most active on Escherichia coli at MIC of 12.5 µg/mL.